Overview
Assurance levels are Prove’s tiered confidence metric, ranging from -1 to 1, that dynamically adapts to user behavior and various authentication keys. It allows for adaptive security policies, meaning you can require different levels of verification for different types of transactions. Reference the following table for a detailed breakdown of each assurance level and its corresponding reason and description.| AL | Reason | Description |
|---|---|---|
| -1 | -1A | Too many identities bound to a single phone number. |
| -1F | Premium rate number globally or listed on the US Override Services Registry (OSR) registry. | |
| -1G | Online rentable temporary eSIM or VoIP number. High activity increases suspicion rather than reducing it. | |
| -1H | Online rentable temporary eSIM or VoIP numbers, with high activity. Equal to AL-1G but these phone numbers are actively used for fraudulent activities. | |
| 0 | 0B | No behavioral data available. Country doesn’t give it. |
| 0C | Assigned number with no behavioral activity. Dormant accounts carry reuse risk. | |
| 0D | Short tenure, no activity. Number likely not yet in use. Lower fraud risk than dormant assigned numbers. Reclassifies to AL0E if activity appears. | |
| 0E | Short tenure with behavioral activity present. | |
| 0F | Activity volume exceeds normal human thresholds. High volume is a bot signal, not a positive one. | |
| 0G | Pagers or other non-standard line types. Behavioral signals incompatible with standard identity verification. | |
| 1 | 1A | Enough ownership tenure and longitudinal human behavior |
| 1B | Tenure and longitudinal human behavior with Prove binding phone to a specific identity, supersedes AL1A | |
| 1D | Low longitudinal behavior but human signals such as ports, calls, or logins indicate not an eSIM bot | |
| 2 | 2A | Prove has seen this phone and identity before at moderate-to-high confidence. |
| 2B | Prove corroborated data across more than one identity data source. | |
| 3 | 3A | Prove has seen this phone and identity before at high confidence, this is this person’s primary number. |